8
$\begingroup$

Elon Musk, SpaceX’s founder and CEO, tweeted minutes later that engineers turned off one of the booster’s 33 engines just before ignition, and another engine “stopped itself.”

“So 31 engines fired overall,” Musk tweeted. “But still enough engines to reach orbit!”

Source: Spaceflight Now article

One engine out after liftoff for this beast of a booster is unlikely to result in mission failure. But is it publicly known whether one engine out on the pad will cause a pad abort (meaning a shutdown of the running engines and termination of the launch attempt)?

Note: Not looking for guesses or unsubstantiated answers.

$\endgroup$
17
  • 6
    $\begingroup$ @TheMatrixEquation-balance you couldn't be more wrong. It's very straightforward - does anyone know if the booster will be allowed to lift off with one engine out, or not? For most vehicles, the answer is no. But "most vehicles" don't have so many engines. $\endgroup$ Commented Mar 1, 2023 at 18:46
  • 3
    $\begingroup$ @TheMatrixEquation-balance that was literally the definition of it in shuttle for proceeding with the launch. You're not helping your argument here. Understandable, because it's wrong. $\endgroup$ Commented Mar 1, 2023 at 19:01
  • 2
    $\begingroup$ Agreed, and nothing in what I wrote references a catastrophic failure in any way. In fact, the title says "failure to start". $\endgroup$ Commented Mar 1, 2023 at 19:05
  • 3
    $\begingroup$ Too bad Tim Dodd isn't hanging around here anymore. $\endgroup$
    – Erin Anne
    Commented Mar 1, 2023 at 21:22
  • 2
    $\begingroup$ thanks for the correction; deleting the ping $\endgroup$
    – Erin Anne
    Commented Mar 3, 2023 at 0:54

1 Answer 1

4
$\begingroup$

According to remarks from Mr. Musk summarized in an article on Ars Technica, at least for the test flight on 4/20/23, the vehicle was allowed to lift off with three engines out, which was the maximum allowed number of engines out to proceed with the launch.

When the rocket lifted off, there were three engines whose ignition was terminated because the flight software did not deem them "healthy enough" to bring to full thrust. That left 30 of the Super Heavy first stage's 33 engines in good condition, which is the minimum allowable number for liftoff.

$\endgroup$
1
  • 1
    $\begingroup$ I didn't know he confirmed it. Then again that was IFT-1 which was a Wild West show. Elon seemed to have gotten restless after years of development, he knew Starship (and for sure the launch pad) still needed work but I suspect he had enough of the speculations he was hearing from the team and pushed them to launch it and find out what happens. I think he just wanted to see if it made it up to (but not including) stage separation, with low expectations beyond that for the first flight. Missing a few engines in that situation didn’t matter. I’m curious though if they would ever do that again. $\endgroup$ Commented Jul 20 at 15:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.